Language detection is really simple. Just minor perl magic:
%Languages = (
'en' => '\b(the|that|and|why|what)\b',
'de' => '\b(der|die|das|und|oder)\b',
'fr' => '\b(et|une|les|ou|est|je|avec|même)\b',
'es' => '((¡|¿)|(\b(por)\b))',
'it' => '\b(il|gli|che|perchè|così)\b',
'se' => '\b(är|från|för)\b',
);To be extended…